Objective: This study aimed to compare two different tooth replacement strategies for partially dentate older patients namely; removable partial dentures (RPDs) and functionally orientated treatment based on the shortened dental arch (SDA) concept. Method: 88 partially dentate older patients (mean age 69.4 years) completed a randomised controlled clinical trial. 43 patients received RPDs and 45 received functionally orientated treatment where resin bonded bridgework was used to provide 10 pairs of occluding contacts. Patients were followed for 1 year after treatment intervention. The impact of treatment on oral health-related quality of life (OHrQOL) and cost effectiveness were used as outcome measures. Each patient completed the short form of the Oral Health Impact Profile (OHIP-14) at baseline, 6 months and 1 year after treatment intervention. All costs involved in providing and maintaining each intervention were recorded including dental laboratory bills, materials and professional time. Result: Both the RPD (p=0.004) and the functionally orientated (p<0.001) treatment groups demonstrated statistically significant improvements in OHrQOL 1 year after treatment intervention. On average 9.4 visits were required to complete and maintain the RPDs over the 1 year period as compared to 5.3 visits for the functionally orientated group. The average laboratory cost for the RPDs was $537.45 per patient versus $367.89 for functionally orientated treatment. The cost of achieving the Minimally Important Difference of 5 scale points in OHIP-14 score with RPDs was $732.17. For the functionally orientated group the cost was $356.88. Therefore, functionally orientated treatment was more than twice as cost effective (1:2.05). Conclusion: For partially dentate older patients, functionally orientated treatment based on the SDA concept resulted in sustained, significant improvements in OHrQOL. Provision of functionally orientated treatment was also more than twice as cost effective compared to conventional treatment using RPDs.